The Mystery of Wave Propagation and Radiation from an Antenna

Abstract

This chapter presents the necessary mathematical formulations, which dictate the space‐time behavior of antennas. It briefly reviews the derivation of the four equations and illustrates how to solve them analytically. The four equations consist of Faraday's law, generalized Ampere's law, generalized Gauss's law of electrostatics, and Gauss's law of magnetostatics, respectively, along with the equation of continuity. To obtain the electromagnetic wave equation, which every propagating wave must satisfy, the chapter summarizes the laws of Maxwell's equations. It defines what is meant by the term radiation and then observes the nature of the fields radiated by point sources and the temporal nature of the voltages induced when electromagnetic fields are incident on them. The chapter describes the impulse responses of transmitting and receiving dipole‐like structures whose dimensions are comparable to a wavelength. It exposes a different picture of electromagnetic wave propagation when the wave strength is much smaller than the ambient noise.